Flexural Behavior of Hollow Pultruded GFRP Box Profiles: An Experimental and Numerical Analysis

Pultruded Fiber Reinforced Polymer (FRP) profiles are increasingly used as structural elements in civil infrastructure. However, the anisotropic elasticity and the application‐driven slenderness make them prone to local buckling failure at loads well below their ultimate capacity. This study adopts a combined experimental and numerical methodology as a design tool to characterize the behavior of hollow pultruded FRP profiles under three-point bending. Experimental tests were first carried out on small-scale (coupon) specimens to determine the most relevant material properties, followed by full-scale loading of simply-supported beams under three-point bending loads. Subsequently, a non-linear finite element analysis (FEA) of the full-scale tests was carried out in ABAQUS to gain more insight into the sequence of damage evolution. In this regard, Hashin’s failure criterion was used to model the failure of composite material. The results show that the structural integrity of hollow pultruded FRP beams is often governed by the local buckling rather than the material strength. In addition, Hashin’s damage criteria proved to be an accurate tool for investigating the failure modes of the hollow pultruded FRP beams. © The Author(s), under exclusive licence to Shiraz University 2024.